ELECTRICAL-PROPERTIES OF PRASEODYMIUM-DOPED GAAS AND AL0.3GA0.7AS EPILAYERS

Praseodymium-doped GaAs and Al0.3Ga0.7As epilayers grown on Semi-Insul ating (SI) GaAs substrates by Liquid Phase Epitaxy (LPE) were first st udied in this present work. Measurement techniques, such as microscopi c observation, X-ray diffraction. Secondary Ion Mass Spectroscopy (SIM S), and Hall measurement were employed. Layers doped with Pr resulted in a mirror-like surface, except several high Pr-doped layers having d roplet surfaces. Hall measurements reveal that the grown layers contai ned p-type layers, carrier concentrations from 6.3 x 10(15) to 1.2 x 1 0(16) cm(-3), and from 6.3 x 10(15) to 3.5 x 10(16) cm(-3) for Pr-dope d GaAs and Al0.3Ga0.7As epilayers, respectively. Although p-type condu ction exists, in the light of electrical features, doping of Pr into t he GaAs and Al0.3Ga0.7As growth melts is still considered to exhibit g ettering properties rather than to become a new acceptor itself. Addit ional photoluminescence examinations were taken. Their results also in dicate that Pr-doped layers produce no new emission lines and support the electrical observations.